If your Facebook feed hasn’t made it clear that engagement season has officially arrived, the wedding gurus at The Knot point out that 39 percent of marriage proposals take place between Thanksgiving and Valentine’s Day. That means the clock is ticking, so we gathered some tips for ring-seekers without a clue.

When it comes to a diamond, shape is subjective, the cut is the key. “The most important thing — above clarity and color — is how well the stone is cut,” said Jack Winer, manager of Lux Bond & Green’s Boston and Wellesley locations. “There’s a mathematical formula to cut a diamond and if you cut the stone correctly, all the light that comes in will bounce back out. You’re going to wear the diamond every single day of your life and when they get dirty, if they’re not cut correctly, the sparkle won’t shine through the dirt.”

Forget trends and hype. . . “I think there was a lot excitement when Kate Middleton got engaged with Princess Diana’s sapphire, but women will always ultimately choose what speaks to them and what they love,” said Jennifer Sciolto, group director for Tiffany & Co. “It’s not the same as fashion trends when you see a celebrity in a dress and you might want to replicate that style. When it comes to rings, it’s more about finding something a woman is going to love on her hand for the rest of her life.”

Advertisement

. . . But don’t rule out custom designs. Megan Flynn of the South End’s M. Flynn said that many of her clients come to her with family stones that they’d like to have set for a custom engagement ring. While the process of designing and creating a custom ring can be daunting, Flynn assured that it can fly by with ease. “If we can zone in on the design, we can have it finished for them in 2 to 3 weeks,” she said, also noting the sentimental value of a ring made from scratch. “When we go to auctions, we see the jewelry that people who are true collectors collect. They were made just for them, and you just don’t see that as much anymore.”

Get The Weekender in your inbox:

The Globe's top picks for what to see and do each weekend, in Boston and beyond.

There’s no correlation between your salary and how much you spend. “That was just advertising that was well done,” Winer said, of the popular conception that an engagement ring should cost two to three months’ salary. “I don’t think there’s any guideline for what you should spend. I think it’s about what people feel comfortable buying or financing.”

Sanity over vanity, guys. Size up: “If it’s going to be a surprise and he doesn’t know her [ring] size, we always like to make sure the ring is a little bit big,” said Winer. “We ask that he brings in a picture or describes the recipient and we make a conservative guess and give him a half size up. Resizing can be done later. You never want the case where the ring won’t fit over her knuckle. It can kill the moment.”

Platinum gives peace of mind: “A majority of our engagement rings [at Tiffany & Co.] are set in platinum. It’s so beautiful and compliments the diamond. If we use gold or rose gold in the design, it’s more for a fashion feature but metal really shouldn’t distract from the stone,” said Sciolto.

Then again, gold — even rose gold — works nicely, too. “Platinum can be very [physically] heavy for people and can scratch. We definitely suggest gold in a lot of cases because it’s lighter and it still wears very well,” said Flynn, who favored yellow gold for her own ring. “In terms of care and maintenance, it’s a toss up so we tell our customers that jewelry just wears and there’s no way getting around that. You need to be responsible with it.”